Image capturing device and activation method therefor

ABSTRACT

An image capturing device includes a first controller operable to control image capturing; an operation section including a switch; a detector operable to detect a change to an image capturing mode and to send a signal representing the change; a second controller operable to monitor and process the sent signal, the second controller having a power consumption less than that of the first controller; and a power supply operable to supply power to the first controller, the second controller, and a functional section of the device. When the second controller receives the signal sent from the detecting section in a power saving state in which power is supplied from the power supply to the second controller, the power saving state is changed to a power supplying state capable of image capturing by supplying power from the power supply to portions of the device including the first controller.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/380,842, filed on Mar. 4, 2009, which is a continuation of U.S.application Ser. No. 11/434,542 filed on May 15, 2006 in the U.S. Patentand Trademark Office which claims priority from Japanese PatentApplication No. JP 2005-142965 filed in the Japanese Patent Office onMay 16, 2005, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

The present invention relates to a technology, used in an imagecapturing device, for enhancing its activating functionality so as notto fail to capture a desired image of a subject or the like andpreventing unnecessary power consumption in a standby state of the imagecapturing device before it enters an image capturing mode.

A camera-device configuration (see, for example, Japanese UnexaminedPatent Application Publication No. 2003-274640) is known which shortensan activation time that is necessary from the time a power-on operationis performed on a camera device until the camera device is actuallyswitched on for use.

When a power supply switch is operated, chattering in which intermittentopening and closing of a contact is repeatedly performed occurs, thuscausing a false operation, etc. Accordingly, after a time passes untileffects of the chattering disappear, a process (so-called “chatteringpreventing process”) that determines whether the power supply switch isopened or closed is performed. In addition, when it is determined thatthe power-on operation has been performed, a system initializing processis performed after power supplied by a system's power supply unitbecomes stable. After that, the camera device is in a state capable ofprocessing such as image capturing. In other words, it is difficult toperform an operation or processing desired by a user unless a timerepresented by “T1+T2+T3” passes after a power-supply operation time atwhich a power-supply operation is performed, where T1 represents a timenecessary for the chattering preventing process, T2 represents a timenecessary until the power supplied by the power supply unit becomesstable, and T3 represents a time necessary for the system initializingprocess.

Therefore, by performing the chattering preventing process after turningon the power supply switch and the system initializing process inparallel, an activation time from the power-supply operation time untilthe operation or processing desired by the user is initiated can beshortened. In other words, by employing a sequence that performs systeminitialization as background processing for the chattering preventingprocess, after the power is supplied to the system, the system can beinitialized without waiting for the chattering preventing process tofinish. For example, when T1<T3, the activation time can be shortened toa time represented by “T2+T3” or approximately a time obtained by addingsome value to “T2+T3.”

However, the image capturing device of the related art has the followingproblems in its activating functionality and power saving function.

For example, cases in which the user misses a shutter releaseopportunity include a situation in which, when the power of the deviceis off at the time the user finds a desired subject, the user fails tocapture an image of a subject due to a long time taken after the userholds the device until the device is ready for image capturing. In otherwords, a time necessary for activation after pressing the power supplyswitch is no more than approximately one second, even if the activationis fast, so that it is difficult to capture an image of a subject (orthe like) passing in a moment. This is because it is difficult to reducethe activation time to zero in an actual device. To prevent the userfrom missing the shutter release opportunity, the system power needs tobe continuously on or the device needs to be in a suspend state. Thesuspend state means a state in which, although an operation of a controlunit such as a CPU (central processing unit) is stopped, the power ofeach portion of the system is on.

As described above, to reduce the activation time close to zero, anincrease in power consumption is extremely important and necessary incompensation for the reduction. Therefore, when a battery-drivenportable device is used, it is necessary for a user to carry manycharged batteries or to use a mass storage battery. In a digital cameraor the like, a device power-saving function is important for capturingas many images as possible. Thus, shortening of the activation time andthe need of power saving conflict with each other.

Accordingly, it is desirable to satisfy both an improvement inactivating functionality and power saving in an image capturing device.

SUMMARY OF THE INVENTION

To solve the above problems, according to an embodiment of the presentinvention, there is provided an image capturing device including firstcontrol means for controlling image capturing, the first control meanshaving a first power consumption; operation means including a switch;detecting means for detecting a change to an image capturing mode andfor sending a signal representing the change to the image capturingmode; second control means for monitoring and processing the signal sentfrom the detecting means, the second control means having a powerconsumption less than the first power consumption; and a power supplyfor supplying power to the first control means, the second controlmeans, and a functional section of the image capturing device.

In the image capturing device, a power saving state is changed to apower supplying state capable of image capturing by supplying power fromthe power supply to portions of the image capturing device including thefirst control means when the second control means receives the signalrepresenting the change to the image capturing mode from the detectingmeans.

According to another embodiment of the present invention, there isprovided an activation method for an image capturing device having afunction of controlling power supplying states including a first powercontrol state capable of image capturing, the first power control statehaving a first power consumption, and a second power control statehaving a power consumption less than the first power consumption. Theactivation method includes, in the second power control state,monitoring a switch operation and a change to an image capturing mode;and, when the change to the image capturing mode is detected in thesecond power control state, changing the second power control state tothe first power control state.

Accordingly, in an embodiment of the present invention, at the time asecond control means receives a detection signal representing a change(changing start) to an image capturing mode, power supply control forenabling image capturing is performed. After changing to a first powercontrol state, image capturing is immediately initiated. In a secondpower control state, power is supplied only to the second control meansand power does not need to be continuously supplied to the first controlmeans and the second control means. This contributes to reducing powerconsumption in a standby state before image capturing.

According to an embodiment of the present invention, by initiatingpreparation for image capturing at the time the setting of an imagecapturing mode is detected, activating functionality can be enhanced. Inaddition, it is not necessary to set a power supplying state capable ofimage capturing at all times. When image capturing is not performed, bysetting a standby state having low power consumption, a power savingeffect can be obtained. In other words, since it is difficult to reducean activation time itself to zero, by changing to the first powercontrol state while using, as a start point, the time the change to theimage capturing mode is detected, both an improvement in activatingfunctionality and power saving can be achieved.

For example, after changing to a power supplying state capable of imagecapturing, when a power supplying operation is not performed, or asignal representing a change to an image capturing mode is not detected,by shutting off power supplied to the first power control means tochange to the power saving state, power consumption in the standby statecan be reduced. In other words, after changing to the first powercontrol state, when a power supplying operation is not performed, or asignal representing a change to an image capturing mode is not detected,by determining that there is no intention of image capturing or a highprobability of no intention, it is preferable to change to the secondpower control state (power saving state).

In addition, according to a configuration in which a sensor fordetecting contact with a device is provided as the detecting means fordetecting the change to the image capturing mode, when it is detected,as a preliminary image capturing step, that the image capturing deviceis touched by a user, the device can be changed to the first powercontrol state. Alternatively, according to a configuration in which asensor for detecting a change in the attitude of a body of the device isprovided as the detecting means, when it is detected, as a preliminaryimage capturing step, that the image capturing device is held or movedby the user, the device can be changed to the first power control state.Furthermore, by employing a detecting form that is a combination ofthese sensors, detection accuracy can sufficiently be enhanced.

In order to obtain a power saving effect in a standby state in whichimage capturing is not performed, it is preferable that, when the secondcontrol means receives a signal representing a change to an imagecapturing mode from detecting means, a power-supply-instruction signalbe sent from the second control means to a power supply after a restingstate of the second control means is canceled.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an example of a basic configuration ofan image capturing device according to an embodiment of the presentinvention;

FIGS. 2A and 2B are perspective views showing contact detection in acamera according to an embodiment of the present invention;

FIGS. 3A and 3B are illustrations of a different example of the contactdetection in a camera according to an embodiment of the presentinvention;

FIG. 4 is an illustration of attitude detection in a camera according toan embodiment of the present invention;

FIG. 5 is an illustration of examples of screens for activationsettings;

FIG. 6 is a flowchart showing a system activating process;

FIG. 7 is a block diagram showing a main part of a configurationexample;

FIG. 8 is a flowchart showing an example of an activation process;

FIG. 9 is a flowchart showing a process flow continued from FIG. 8;

FIG. 10 is a block diagram showing a main part of another configurationexample;

FIG. 11 is a flowchart showing a main part of an example of a systemactivation process concerning the configuration shown in FIG. 10;

FIG. 12 is a block diagram showing a main part of still another exampleconfiguration;

FIG. 13 is a flowchart showing a main part of an example of a systemactivation process concerning the configuration shown in FIG. 12;

FIG. 14 is an illustration of examples of settings for activation;

FIG. 15 is a flowchart showing a main part of an example of a systemactivation process in a case in which a high speed mode is set; and

FIG. 16 is a flowchart showing a main part of an example of a systemactivation process in a case in which a maximum speed mode is set.

DETAILED DESCRIPTION

In an embodiment of the present invention, by immediately controllingpower supply when detecting setting of an image capturing mode with adetecting unit such as an electrostatic sensor or angular velocitysensor, image capturing can be initiated after necessary processing suchas initialization. For example, at the time a user holds a camera,supplying of power to each portion of a camera system and aninitializing process are initiated, whereby it takes almost no waitingtime after operating a power supply switch until operating a shutterrelease button. This can prevent occurrence of a situation in which theuser misses a shutter release opportunity. An embodiment of the presentinvention is widely applicable to still cameras and camcorders, or tovarious types of image capturing devices that can capture still andmoving images.

FIG. 1 shows an example of a basic configuration of an image capturingdevice according to an embodiment of the present invention.

An image capturing device 1 includes an operation unit 2 including powersupply switches and a detecting unit 3 using an electrostatic sensor, anangular velocity sensor, etc. Signals sent from these sensors are sentand processed in a system controller 4.

The operation unit 2 includes various types of operation buttons andswitches provided on the image capturing device 1. In FIG. 1, only powersupply switches 2 a and 2 b are shown. An operation signal from a powersupply switch (or a power switch) serves as a trigger signal forsupplying power. When an embodiment of the present invention is appliedto, for example, a digital still camera, the number of power supplyswitches is not limited to one depending on a configuration form, butthere is a system including a plurality of power supply switches. Inthis embodiment, two switches are shown.

The detecting unit 3 is provided to detect a change in mode to an imagecapturing mode. The detecting unit 3 may have the following forms:

-   (I) form using sensor for detecting contact with image capturing    device 1;-   (II) form using sensor for detecting change in attitude of image    capturing device 1; and-   (III) form Using form (I) and form (II).

At first, in form (I), for example, a contact detecting sensor 3 a suchas an electrostatic sensor is used. The contact detecting sensor 3 adetects contact of a user with the image capturing device 1, and sends asignal of the detection to the system controller 4. Excessive detectionsensitivity causes a situation in which slight contact with the imagecapturing device 1 performs power supplying for activation, so that thefrequency of false detection increases, etc. Thus, it is preferable toappropriately set the detection sensitivity to ensure contact detection.

Also in the above form (II), an attitude detecting sensor 3 b, such asan angular velocity sensor or gyrosensor, is used. The attitudedetecting sensor 3 b detects a change in device attitude when the imagecapturing device 1 is held or moved by the user, and sends a signal ofthe detection to the system controller 4. Cases to which an embodimentof the present invention is applied include a form in which, not onlythe angular velocity sensor, but also an acceleration sensor is used asa sensor capable of measuring a change in speed, and a form in whichdetection accuracy is enhanced by using a vibration sensor to increasethe number of detection axes. Alternatively, in a camera device havingan image stabilizing function, by using an angular velocity sensor andacceleration sensor provided for image stabilization to detect a changein device attitude, a detecting unit can be mounted without increasingthe number of components and expense.

Improvement of the detection accuracy includes a method that uses aplurality of sensors of the same type in the above forms (I) and (II),and a method that uses sensors of different types in combination, as inform (III). When determination is multilaterally performed, the latteris more effective.

In FIG. 1, for brevity of description, form (III) is assumed, and anexample of the detecting unit 3 in which it includes sensors of pluraltypes is shown. In addition, forms of transmission from the detectingunit 3 to the system controller 4 include analog transmission anddigital transmission (including binarization communication and serialcommunication), whose details are described later.

The system controller 4 includes a first control unit 4 a and a secondcontrol unit 4 b. The configuration of the system controller 4 has, forexample, the following forms:

a form in which each control unit is formed as a separate circuit; and

a form in which the system controller 4 is formed as a single chip andcircuit portions having functions of both control units are formed inthe single chip.

In either form, the first control unit 4 a controls image capturing, orrecording or playback of captured image data, and the second controlunit 4 b monitors and processes an operation input signal from theoperation unit 2 and a detection signal from the detecting unit 3. Forexample, a microcomputer or the like may be used as the first controlunit 4 a. For example, an application specific IC (integrated circuit),a microcomputer (used as a sub-computer for a main computer used as thefirst control unit 4 a), or the like, may be used as the second controlunit 4 b.

In a system configuration unit 5 under the control of the first controlunit 4 a, various types of components are used depending on thespecifications and system configuration of the image capturing device 1.In this embodiment, an image signal processing section 5 a and an imagedisplay section 5 b are shown as typical examples. The image signalprocessing section 5 a includes an image capturing unit, a camera signalprocessor, and a recording-and-playback-system signal processor, andperforms image capturing, and image recording and playback, and, in theimage display section 5 b, an LCD (liquid crystal display) panel or thelike is used.

A power supply 6 supplies power to the first control unit 4 a, thesecond control unit 4 b, and the system configuration unit 5. Inapplication of an embodiment of the present invention, a power supply 6a in which, for example, a battery (primary battery or secondarybattery), a fuel cell, or the like, is used, and a power-supply voltagegenerating section 6 b (such as a DC-DC converter) for generating apower-supply voltage necessary for each circuit are providedirrespective of the circuit configuration of the power supply 6. Thepower-supply voltage generating section 6 b supplies power to eachcircuit through power-supply lines.

In this embodiment, when the power supply 6 a supplies power to thepower-supply voltage generating section 6 b in a state in which abattery pack or the like is installed in the image capturing device 1,power supply from the power-supply voltage generating section 6 b to thesecond control unit 4 b can be immediately performed.

The second control unit 4 b has power consumption less than that of thefirst control unit 4 a. This is because, since the second control unit 4b handles monitoring and processing the operation signal and thedetection signal, unnecessary power consumption is prevented in astandby state before image capturing. When, for example, a microcomputeris used as the second control unit 4 b, a consumption current is set tohundred microamperes or less.

Unlike that, an arithmetic operation unit having a fixed operatingfrequency, or an arithmetic operation unit in which power control can beperformed by variably controlling an operating frequency is used as thefirst control unit 4 a. When acceleration of processing or the like ispreferentially performed, the power consumption of the first controlunit 4 a increases than that of the second control unit 4 b. In otherwords, if the image capturing device 1 is set in a mode capable of imagecapturing at all times by performing a power-supply operation (by theuser) to supply power to the first and second control units 4 a and 4 b,and the system configuration unit 5, a situation in which the usermisses a shutter release opportunity can be avoided. However, powerconsumption in the above case is large, thus shortening a time in whichthe image capturing device 1 can be battery-driven. Accordingly, in thestandby state before image capturing, by supplying power from the powersupply 6 a to the second control unit 4 b having less power consumption,a power saving effect can be obtained.

In an embodiment of the present invention, in a power saving mode inwhich power is supplied from the power supply 6 a to the power-supplyvoltage generating section 6 b, when the second control unit 4 breceives, from the detecting unit 3, a signal representing a change inmode to the image capturing mode, the power supply 6 supplies power tothe first control unit 4 a and the system configuration unit 5, and thepower saving mode subsequently changes to a power supplying statecapable of image capturing. Specifically, power control states of theimage capturing device 1 include at least the following states:

a first power control state (hereinafter referred to as “1S”) in whichthe image capturing device 1 is capable of image capturing; and

a second power control state (hereinafter referred to as “2S”) havingpower consumption less than that in 1S.

In 1S, power supply from the power supply 6 to the system controller 4and the system configuration unit 5 is performed, so that powerconsumption is greater than that in 2S.

Also, in 2S, power supply from the power supply 6 to the second controlunit 4 b is performed and power supply to the first control unit 4 a andthe system configuration unit 5 is not performed. In other words, 2S isa power saving state which monitors a switch operation by the operationunit 2 and a change in mode to the image capturing mode by the detectingunit 3. When the change in mode to the image capturing mode is detectedin this control state, that is, when a detection signal by the detectingunit 3 is sent as a trigger signal to the second control unit 4 b,control of change from 2S to 1S is performed.

This performs power supplying to the first control unit 4 a andinitialization, power supplying to the system configuration unit 5, etc.After that, the image capturing device 1 changes to the power supplyingstate capable of image capturing. In this state, by turning on the powersupply switch and pressing a shutter release button, image capturing canbe instantly initiated. In addition, in 1S, when the power-supplyoperation by the power supply switch is not performed, or the signalfrom the detecting unit 3 which represents the change in mode to theimage capturing mode is not received, 1S automatically changes into 2S.In other words, by shutting off supplying the power to the first controlunit 4 a and the system configuration unit 5, 1S changes into the powersaving state (2S).

For brevity of description, in only 1S, the image capturing can beperformed. However, in application to a configuration form in which apower saving effect can be set in stages or continuously by operatingfrequency control or device power-supplying control, the power controlstate can be divided depending on the level of the power consumption.Specifically, 1S can be divided into two or more classes.

Although, in this embodiment, a configuration in which the operationsignal with the power supply switch 2 a is sent and processed in thesecond control unit 4 b has been described, the embodiment of thepresent invention can be practiced in various configurations such as aconfiguration in which the operation signal from the power supply switch2 a is sent and processed in the first control unit 4 a.

Next, an example of a power-supply control sequence of the imagecapturing device 1 is described below, with it divided into thefollowing three cases:

-   (a) case A in which, after detecting that the image capturing mode    is set, the power supply switch 2 a is operated by the user to    initiate image capturing;-   (b) case B in which, although it is detected that the image    capturing mode is set, the power supply switch 2 a is not operated    by the user after that; and-   (c) case C in which detection of the image capturing mode in being    set and a user's operation on the power supply switch 2 a are    performed approximately at the same time.

At first, case A is described in accordance with the following steps (1)to (7). In FIG. 1, the numerals in the parenthesized symbols correspondto the following parenthesized numerals 1 to 7, respectively, andrepresent processing order with the lapse of time.

(1) By inserting a battery into the power supply 6, the power of thepower-supply voltage generating section 6 b is turned on.

(2) Power supply from the power-supply voltage generating section 6 b tothe second control unit 4 b is performed, whereby the second controlunit 4 b is ready to receive the operation signal from the power supplyswitch 2 a.

(3) The second control unit 4 b is notified by the detecting unit 3 thatthe image capturing device 1 is in the image capturing mode. Forexample, in form (I), an electrostatic sensor or the like is used fordetecting contact with the image capturing device 1. In other words,detection of contact with the image capturing device 1 by using thesensor performs system activation. For example, a system activationprocess is performed as a background process. In addition, in form (II),an angular velocity sensor or the like is used for detecting a change inattitude of the image capturing device 1. Detection with the sensor of astate in which the image capturing device 1 is raised by the user and isready for image capturing, system activation is performed. For example,a system activation process is performed as a background process.

When receiving, from the detecting unit 3, a signal indicating that theimage capturing mode is set, the second control unit 4 b instructs thepower-supply voltage generating section 6 b to perform power supply tothe first control unit 4 a and the system configuration unit 5 bysending a signal to the power-supply voltage generating section 6 b.

(5) After being instructed by the second control unit 4 b, thepower-supply voltage generating section 6 b initiates supplying power tothe entire system. In other words, power is supplied to the firstcontrol unit 4 a and the system configuration unit 5.

(6) When the entire system is sufficiently supplied with power, eachcomponent is operable, thus enabling signal transfer between the firstcontrol unit 4 a and the second control unit 4 b, and signal transferbetween the first control unit 4 a and each of the image signalprocessing section 5 a and image display section 5 b of the systemconfiguration unit 5.

(7) When the power supply switch 2 a is operated by the user, a signalof the operation is transferred to the second control unit 4 b. Thesignal is transferred from the second control unit 4 b to the firstcontrol unit 4 a, so that the image capturing device 1 instantly changesinto a state capable of initiating image capturing.

In this embodiment, when the detecting unit 3 detects that the imagecapturing mode is set in the image capturing device 1, power can besupplied to the components including the first control unit 4 a in sucha manner that the second control unit 4 b instructs the power-supplyvoltage generating section 6 b. However, the sequence is not limitedthereto, but may employ a method in which the system is set to a suspendstate before image capturing and a method in which the operating speedof the first control unit 4 a is reduced. In this case, when thedetecting unit 3 detects that the image capturing mode is set in theimage capturing device 1, the system is returned to a state capable ofimage capturing, or an increased operating speed of the first controlunit 4 a sets the image capturing device 1 to be in an image capturingstate without any difficulty. Hence, although a time necessary forsystem activation is shortened, in the standby state in which it is notdetected that the image capturing mode is set, power consumptionincreases compared with the above case.

Next, although, in case B, for example, when the user touches the imagecapturing device 1 but does not press any power supply switch, the steps(1) to (6) are performed, power is consumed more than necessary if thesystem is being activated in this state. Accordingly, when thepower-supply operation is not performed, or the signal from thedetecting unit 3 that represents a change in mode to the image capturingmode is not set, the present state is changed to the above 2S (powersaving state). For example, in cases such as when a detection signalrepresenting a touch of the user on the image capturing device 1 is notsent to the second control unit 4 b during a predetermined time, powerto the first control unit 4 a and the system configuration unit 5 isshut off without any explicit operation instruction. For example,supplying of power to the portions of the system excluding the secondcontrol unit 4 b is stopped in the background processing withoutnotifying the user. In this state, under the control of the secondcontrol unit 4 b, the image capturing device 1 is set in a mode thatmonitors an operation signal and a detection signal. The powerconsumption is at a minimum level that is necessary for processing bythe second control unit 4 b. After that, when a touch of the user on theimage capturing device 1, that is, the image capturing mode in being setin the image capturing device 1, the process proceeds from step (3) tostep (4) and thereafter.

In case C, for example, when a state in which the user touches the imagecapturing device 1 and a state in which the user presses the powersupply switch occur simultaneously or approximately simultaneously, thesystem activating process is performed as in the related art, and theimage capturing mode is set in the image capturing device 1 without anydifficultly. In other words, in a configuration form in which the secondcontrol unit 4 b continuously monitors an operation signal and adetection signal, the start of changing to the image capturing mode isdetected by the detecting unit 3, and, even if the power supply switch 2a is simultaneously pressed, both can be grasped by the second controlunit 4 b. Thus, after changing “7” in the parenthesized symbol in FIGS.1 to “3,” processing after the above (4) is performed.

When the start of changing to the image capturing mode is not detectedat all, for example, when the user does not touch the image capturingdevice 1 in form (1), in the above (3), a detection signal indicatingthat the image capturing mode is set in the image capturing device 1 isnot sent to the second control unit 4 b. Thus, system activation, thatis, supplying power to the first control unit 4 a, an initializingprocess, and supplying power to each portion of the system configurationunit 5 are not performed (the image capturing device 1 enters apower-controlled state in which the power consumption is the lowest).

Although various states depending on usage of the image capturing device1 are assumed, the second control unit 4 b sets power management and apower control sequence, whereby, in any state, the image capturingdevice 1 can be changed to a state capable of image capturing byactivating the system without any difficulty.

FIGS. 2A to 16 show an example in which an embodiment of the presentinvention is applied to a digital camera or the like.

FIGS. 2A and 2B show, as an example of form (I), an example of aconfiguration using an electrostatic sensor or the like. FIG. 2A is aperspective view of a camera 7, and FIG. 2B is a perspective back viewof a front portion 8 a of a camera housing 8.

In this embodiment, an image capturing portion 9 is provided on thefront portion 8 a, and in the front portion 8 a, the contact detectingsensor 3 a, such as an electrostatic sensor, is embedded in an area inwhich user's fingers touch a back side in the image capturing mode.

In this case, it is important to know contact of the user's fingerswithout false detection. In other words, excessively enhancing thesensitivity of a sensor IC (or the like) mistakenly detects approach ofa part of a human body other than the fingers.

Accordingly, it is preferable to lower the sensor sensitivity and it ispreferable to broaden a sensor-detecting area, that is, an area forsensing a touch of the user. For example, an amount of detection(electrostatic amount) obtained when the user's fingers touch the areais stored and, when the amount of detection exceeds a predeterminedthreshold value, it can be determined that the amount of detectionrepresents the start of changing to the image capturing mode. When theamount of detection is equal to or less than the threshold value, it canbe determined that the amount of detection represents unexpected contactor approach, or the like.

This embodiment has no problem when a housing is made of, for example,synthetic resin such as plastic. The housing may be coated with anelectrostatic shield depending on a device form, and it is difficult touses the electrostatic sensor to detect contact.

In such a case, a configuration in which, as shown in FIG. 3A, thecontact detecting sensor 3 a is embedded in a surface of a portion thatthe user's fingers touch, for example, the front portion 8 a, isemployed, and a configuration in which, as shown in FIG. 3B, the contactdetecting sensor 3 a is embedded in a back portion 8 b, in which adisplay portion 10 and an operation portion 11 are provided, isemployed. For example, an electrically conductive film element may beused as a detecting element. However, the detecting element is notlimited to the film element but a detecting element formed of variouselectrically conductive materials may be used.

FIG. 4 shows, as an example of form (II), an example of a configurationusing a triaxial acceleration sensor.

In a camera 7B in this example, an attitude detecting sensor 3 b that isprovided on a front portion 8 a or a back side thereof detects changesin X, Y, and Z axes shown in FIG. 4. In other words, user's entering theimage capturing by holding the camera 7B is detected as a change inspeed caused by a change in attitude, that is, acceleration.

The configuration is not limited to the use of the triaxial sensor but abiaxial angular velocity sensor or the like may be used. In addition, anangular velocity sensor and acceleration sensor for detecting motionblurring may also be used. The more the number of axes for detection is,the higher accuracy the detection can have. However, considerations,such as reserving an installation space and an increase in cost, arenecessary.

Next, an example of settings concerning system activation is describedin accordance with examples of screens shown in portions (A) to (G) ofFIG. 5. Although applying an embodiment of the present invention isirrelevant to a system activation setting method, places for settings,etc. In the following examples, a case in which a new item (hereinafterreferred to as “INSTANT START”) is added to a setting screen displayedon a display portion is described below.

Portion (A) of FIG. 5 shows a screen displayed at the time of changingto a setup screen. A range indicated by the broken line rectangleindicates an item being presently selected by a user.

When the user uses an operation portion (see, for example, the operationportion 11 shown in FIG. 3B), such as a cross key, to perform a“downward” operation, a selected position of an indicator (icon) on aleft tool bar downwardly moves, and the screen displayed in portion (B)of FIG. 5 is displayed. In part of the screen on the right side of theindicator, the item “INSTANT START” is displayed.

When the user uses the operation portion, such as the cross key, toperform a “right directional operation” while intending to select“INSTANT START,” as shown in portion (C) of FIG. 5, the item “ENLARGEICONS” at the top of a main part of the screen is selected. However,what the user intends to select is not the item. Accordingly, by usingthe cross key to perform a “downward” operation, as shown in portion (D)of FIG. 5, the cursor is moved to the item “INSTANT START” (this item isset to “NORMAL” in this example).

When the user operates the “right” directional operation in a state inwhich the cursor is positioned at the item “INSTANT START,” as shown inportion (E) of FIG. 5, it can be selected whether to enable (see “ON” inportion (E) of FIG. 5) or disable (see “OFF” in portion (E) of FIG. 5)the setting of “INSTANT START.”

Since, in this example, the item has been set to “OFF,” the user usesthe cross key to perform the “downward” operation. In this operation, asshown in portion (F) of FIG. 5, the setting can be enabled, that is, thecursor can be positioned at “ON.”

When the user intends to confirm the selected item, that is, the item“INSTANT START” needs to be set to “ON,” by pressing a center portion(determination button) of the cross key, the screen displayed in portion(G) of FIG. 5 is displayed and the setting operation finishes.

These consecutive operations can set the item “INSTANT START” to beenabled (“ON”).

Although, in this example, in selecting “INSTANT START,” its enabling ordisabling is displayed with a name of “ON” or “OFF,” obviously, thename, settings, etc., can be freely altered in accordance with anapplication design. In addition to a form in which item setting isperformed on the setup screen, enabling in various configurations ispossible such as a configuration provided with a dedicated toggle buttonand a configuration in which, by providing a contact detecting unit,such as a touch panel, on a display surface, a desired item can beselected on a screen by the user.

FIG. 6 is a flowchart illustrating the system activating process.

In step S1, it is determined whether or not an operation signal from apower supply switch or a detection signal from a contact detectingsensor or attitude detecting sensor has been sent to the system (see,the second control unit 4 b in FIG. 1). If the operation signal or thedetection signal has been sent, the process proceeds to step S2 or S4.If not, monitoring the operation signal or the detection signal iscontinued (this state corresponds to the control state 2S and the powersaving mode is set).

When changing to the image capturing mode is predicted on the basis ofthe detection signal, the process proceeds to step S2 and supplyingpower to the system controller 4 and a system configuration unit andinitialization are initialized as background processing. In addition, ina predetermined time, for example, within one second), a state capableof image capturing is set (this state corresponds to the control state1S), and the process proceeds to step S3.

When a power-supply instruction is issued by operating an operationswitch, the process proceeds to step S4, and the system activationprocess is normally performed (this is similar to that in the relatedart) before the process proceeds to step S5.

In step S3, it is determined whether or not the operation switch hasbeen operated within a predetermined time. In addition, when thepower-supply instruction has been issued before a predetermined set timepasses, the process proceeds to step S5. Even if the set time has passed(at timeout), when the power-supply instruction has not been issued, theprocess returns to step S1. Determination of whether the operationsignal from the operation switch has been sent is performed until theset time passes.

In step S5, an operation of the system configuration unit, for example,the image signal processing section 5 a, is completed, and a backlightor the like included in the image display section 5 b emits light todisplay a screen.

It takes almost no time from the time the power supply switch isperformed in step S3 until changing to step S5 is performed. In otherwords, instantly after the user operates the power supply switch, imagecapturing preparation is established.

Processing to step S6, it is determined whether or not animage-capturing-instruction signal has been sent to the system bypressing a shutter release button. If the image-capturing-instructionsignal has been sent to the system, the process proceeds to step S7 andan image capturing process is initiated.

When, in step S1, both the operation signal from the power supply switchand the detection signal from the sensor are approximatelysimultaneously input, for example, the operation signal from the powersupply switch is preferentially used and the process proceeds to S4.

This example has a feature in processing path proceeding from step S1 inthe order of “steps S2, S3, and S5.” In a configuration of the relatedart, even if, in step S1, the power supply switch is operated so as notto miss capturing an image of a subject, it is difficult for the processto proceed to step S5 unless the waiting time in step S4 passes.Accordingly, a situation in which a shutter release opportunity ismissed during that time occurs.

Next, an example of a configuration in which a signal detected by usingan electrostatic sensor or angular velocity sensor concerning changingto the image capturing mode is sent to the system controller 4 isdescribed.

Transmitting forms for using the angular velocity sensor or the like tonotify the system that the user holds and sets a camera to be ready forimage capturing include, for example, the following systems:

(1) analog system; and(2) digital systems:

(2-1) binarization system; and

(2-2) serial system.

Comparisons in power among the systems are represented by “the (1)analog system”>“the (2-2) serial system”≧“the (2-1) binarizationsystem.” As is clear, the digital systems are less in power consumptionthan the analog system. This is because power is increased for reasonssuch as the need to cause an A/D converter to operate. In addition, inthe binarization system, detection in the system is simple since twosignal levels, High and Low, are used. Accordingly, it has an advantagein that, in a state in which image capturing is not performed, thesystem is continuously set in a sleep mode.

FIG. 7 is a block diagram showing a configuration example 12 in the (1)analog system, and shows a detecting unit 13 and the second control unit4 b in the system controller 4.

In the detecting unit 13, for example, an electrostatic sensor servingas a contact detecting sensor 3 a, an angular velocity sensor serving asan attitude detecting sensor 3 b, etc., are used, and each sensor outputis sent as an analog signal to an IC or computer forming the secondcontrol unit 4 b.

The second control unit 4 b includes, in its circuit configuration, anA/D converter 14, a comparator 15, an arithmetic processing section 17(such as a CPU (central processing unit) core, or an ASIC (applicationspecific IC)).

The A/D converter 14 receives and converts the analog signal from thedetecting unit 13 into a digital signal, and sends the digital signal tothe comparator 15.

In a data storage section 16, threshold data to be sent to thecomparator 15 is stored by using a data writing device 18. As the datastorage section 16, for example, a nonvolatile storage device, such asan EEPROM (electronically erasable and programmable read only memory),is used. By writing threshold data in shipping in units of devices, aproblem of detection error caused by variation in sensor characteristicsand device-unique variation in production, malfunction, or the like, canbe prevented (reliability is enhanced compared with a case using thesame threshold data at all times). In addition, forcing surface mountedcomponents to be changed after a product is completed needs a componentcost and time, thus causing a production cost. However, ability to usesoftware processing with a CPU to alter set values or the like bywriting data to the nonvolatile storage device produces an advantage inthat, even after hardware is completed, adjustment, setting alternation,etc., can be freely performed. In addition, by describing conditionalbranching in a program concerning ambient environments such as anoutside air temperature, flexible responses can be performed.

Threshold data read from the data storage section 16 is sent to thecomparator 15 and is compared with data (sensor detection data)digitized by the A/D converter 14. When the detection data satisfies acondition represented by the threshold data, it is recognized that, forexample, the user touches a predetermined area of the camera, orchanging to the image capturing mode is initiated such that the userholds the camera, and an interruption signal to the arithmeticprocessing section 17 is generated. In addition, when the detection datadoes not satisfy the condition represented by the threshold data, it isdetermined that the image capturing mode is not set, or temporary oraccidental contact or change in attitude or disturbance such as noiseoccurs.

In response to the interruption signal from the comparator 15, a sleepstate of the CPU core forming the arithmetic processing section 17 iscanceled (wakeup), and a system operation is performed with originalperformance that can be exhibited.

Detection data sampling may be performed in a wakeup state at all timeswithout setting the CPU core or the like to be in the sleep state, butpower consumption at that time is an issue. In other words, when powerconsumed for a continuous operation of the CPU core, ASIC, or the like,is an issue, it is preferable to sufficiently lower the operatingfrequency, or it is preferable to set the CPU core or ASIC to the sleepstate or a resting state so that power consumption is set to a valueclose to almost zero. However, since it is not allowed to stop supplyingpower to the A/D converter 14, the comparator 15, and the data storagesection 16, minimum power at which comparison operations between dataconverted by the A/D converter 14 and the threshold data read from thedata storage section 16 is guaranteed is consumed at all times. In otherwords, the second control unit 4 b consumes only minimum necessary powerin its standby state, and, when the second control unit 4 b receives asignal representing changing to the image capturing mode from thedetecting unit 13, the second control unit 4 b cancels its resting stateand sends a power-supply-instruction signal to a power supply. Byperforming an intermittent operation to such an extent that detection isprevented from failing, the power consumption can be reduced.

FIGS. 8 and 9 are flowcharts showing an example of a system activationprocess concerning the (1) analog system.

At first, in step ST1 in FIG. 8, after an analog signal is sent from thedetecting unit 13 to the A/D converter 14, a digital signal obtained inconversion by the comparator 15 is sent to the comparator 15. Inaddition, threshold data is sent from the data storage section 16 to thecomparator 15, and both are compared by the comparator 15. If thedetection data satisfies a condition defined by the threshold data, theprocess proceeds to step ST2. If not, the detection is continuouslymonitored.

In step ST2, the comparator 15 generates an interruption signal for thearithmetic processing section 17, and, in the next step, the sleep stateis canceled. In other words, the process proceeds to step ST3, and astate in which the arithmetic processing section 17 can performprocessing with a predetermined operating speed. The process proceeds tostep ST4.

In step ST4, it is determined whether or not the operation signal fromthe power supply switch has been sent to the second control unit 4 b. Ifthe operation signal has not been sent, the process proceeds to stepST5. If the operation signal has been sent, the process proceeds to stepST9.

In step ST5, supplying power to the system controller and the systemconfiguration unit, initialization, etc., is initiated so as not to benoticed by the user (background processing). The device becomes readyfor image capturing within a predetermined time, and the processproceeds to step ST6.

In step ST6, it is determined whether or not an operation on the powersupply switch has been performed within a predetermined time. When apower-supply instruction is issued before a predetermined set timepasses, the process proceeds to step ST10. Even if the set time haspassed, when the power-supply instruction is not issued (at timeout),the process proceeds to step ST7. Determination concerning the operationsignal from the power supply switch is performed until the set timepasses.

In step ST7, the CPU core or the like forming the arithmetic processingsection 17 is set to the sleep state. After that, the process returns tostep ST1 in FIG. 8.

On the condition that, as shown in step ST8, when the power supplyswitch is operated, an external interruption signal is generated toreturn the arithmetic processing section 17 to a state capable ofprocessing with the predetermined operating speed, in step ST9, thesystem activation process is normally performed in accordance with thepower-supply instruction (this process is similar to that in the relatedart) before the process proceeds to step ST10.

In step ST10, the operation of the system configuration unit, forexample, the image signal processing section 5 a, is completed. Abacklight, or the like, included in the image display section 5 b emitslight to display a screen.

It takes almost no time from the time the power supply switch isperformed in step ST6 until the process proceeds to step ST10. In otherwords, instantly after the user operates the power supply switch, imagecapturing preparation is established.

The process proceeds to step ST11, and, in step ST11, on the basis of anoperation on the shutter release button, it is determined whether or notan image capturing instruction has been issued. If animage-capturing-instruction signal has been sent to the system, theprocess proceeds to step ST12 and an image capturing process isinitiated.

In the (1) analog system, by allowing the system controller to havethreshold data, flexible determination using software can be performed.Accordingly, a detected value obtained by the detecting unit 13 can beused for other uses such as image stabilizing. In addition, thedetecting unit 13 does not need to include any communication circuit forcommunicating with a comparator and the system controller. Thus, thedetecting unit 13 has an advantage in reducing the size of the detectingunit 13, reducing the number of components, and reducing an area andspace for installation.

Next, the (2) digital system is described below.

FIG. 10 is a block diagram showing a main part of an exampleconfiguration 12A of the (2-1) binarization system.

A detecting unit 13A includes a data storage section 16 and a comparator15 other than sensors. An electrostatic sensor serving as a contactdetecting sensor 3 a and an angular velocity sensor serving as anattitude detecting sensor 3 b are used. Each sensor output signal issent to the comparator 15.

The data storage section 16 stores threshold data that is written inshipping by a data writing device 18. The threshold data is read andsent to the comparator 15.

The comparator 15 performs comparison operations between a sensordetection signal and a signal representing the threshold data. As aresult, when the sensor detection value satisfies a conditionrepresented by the threshold data, it is recognized that, for example,the user touches a predetermined area of a camera, or changing to theimage capturing mode is initiated such that the user holds the camera. Abinary signal (e.g., an H-level signal) representing the result of therecognition is output to the second control unit 4 b. When the sensordetection value does not satisfy the condition represented by thethreshold data, it is determined that the image capturing mode is notset, or temporary or accidental contact or change in attitude ordisturbance such as noise occurs. A binary signal (e.g., an L-levelsignal) representing the signal is output to the second control unit 4b.

In addition to the configuration using the data storage section 16 forstoring the threshold data, there is, for example, a configuration inwhich a threshold value is set by adjusting, in shipping, a constantvalue set for the comparator 15 by an external circuit 19. In FIG. 10,both configurations are shown for brevity of description.

A second control unit 4 b includes an interruption generating section 20and an arithmetic processing section 17 (such as a CPU core or ASIC). Anoutput signal of the comparator 15, that is, a binarized signal, is sentto the interruption generating section 20. When the interruptiongenerating section 20 receives a signal representing the start ofchanging to the image capturing mode, the arithmetic processing section17 is interrupted to cancel a sleep state, so that the arithmeticprocessing section 17 enters a state in which the CPU core or the likecan perform processing with a predetermined operating speed.

FIG. 11 is a flowchart showing a main part of an example of the systemactivation process concerning the (2-1) binarization system. FIG. 11shows only differences from the example described concerning the (1)analog system.

In step ST20, the comparator 15 compares the sensor detection signal anda threshold data signal. If the sensor detection value satisfies acondition defined by the threshold value, the process proceeds to stepST21. If not, the sensor detection signal is continuously monitored.

In step ST21, in response to the binary signal from the comparator 15,the interruption generating section 20 generates an interruption signalfor the arithmetic processing section 17, and the sleep state of thearithmetic processing section 17 is canceled. This allows the arithmeticprocessing section 17 to perform processing with a predeterminedoperating speed in step ST22. After that, the process proceeds to stepST4 in FIG. 9.

The subsequent processing is as described with reference to FIG. 9.However, after, in step ST7, the CPU core or the like forming thearithmetic processing section 17 is set to the sleep state, the processreturns to step ST20 in FIG. 11. In the sleep state, the powerconsumption is low since only the interruption generating section 20operates in the second control unit 4 b.

FIG. 12 is a block diagram showing a main part of an exampleconfiguration 12B in the (2-2) serial system.

Differences from the configuration shown in FIG. 10 are described below.

A detecting unit 13B includes a serial communicator 21 at a stage aftera comparator 15.

A second control unit 4 b includes aserial-communication-and-interruption-generating section 22 forexchanging information with the serial communicator 21.

In a configuration in which an arithmetic processing section comparesdetection data sent as serial data from the detecting unit 13B withthreshold data stored in a data storage section 16, the data storagesection 16 is included in a second control unit 4 b, and, in shipping, adata writing device 18 is used to write the threshold data or the likein the data storage section 16. For example, a comparator 15 in thedetecting unit 13B is not necessary and a sensor detection signal issent to the second control unit 4 b through the serial communicator 21.

In this example, the data storage section 16 for storing the thresholddata may be provided in the detecting unit 13A similarly to FIG. 10. Forbrevity of description, FIG. 12 shows both a configuration in which thedata storage section 16 for storing the threshold data is provided inthe second control unit 4 b, and a configuration in which a thresholdvalue is set by adjusting, in shipping, a constant value set for thecomparator 15 by an external circuit 19. In a form that uses bothcomparison using the comparator 15 in the detecting unit 13B andcomparison performed by the arithmetic processing section 17 using thedata storage section 16, Implementation of double determination canenhance reliability, and is useful in verifying a determination resultand backing up the comparison (for example, when the comparator 15malfunctions).

The comparator 15 or the arithmetic processing section 17 performscomparison operations between the sensor detection value and thethreshold data. When the result of the comparison indicates that thesensor output value satisfies a condition represented by the thresholddata, it is recognized that, for example, the user touches apredetermined area of a camera, or changing to the image capturing modeis initiated such that the user holds the camera. Data representing therecognition result or the sensor detection data is transmitted from theserial communicator 21 to theserial-communication-and-interruption-generating section 22. If thesensor output value does not satisfy the condition represented by thethreshold data, it is determined that the image capturing mode is notset, or temporary or accidental contact or change in attitude ordisturbance such as noise occurs. Data representing the result or thesensor detection data is transmitted from the serial communicator 21 tothe serial-communication-and-interruption-generating section 22. Varioustypes of formats (SIO, UART, 12C, etc.,) may be used for a serialcommunication format.

In a form in which the detecting unit 13B includes the comparator 15,when the serial-communication-and-interruption-generating section 22receives, for example, the signal representing the start of changing tothe image capturing mode, the arithmetic processing section 17 isinterrupted to cancel its sleep state, whereby the CPU core or the likeis in a state capable of performing processing with a predeterminedoperating speed.

In a form in which the second control unit 4 b includes the data storagesection 16, when the serial-communication-and-interruption-generatingsection 22 receives the sensor detection data, an interruption isgenerated allowing the arithmetic processing section 17 to compare thesensor detection value and the threshold value from the data storagesection 16. As a result, when it is determined that changing to theimage capturing mode is started, the CPU core or the like is in a statecapable of performing processing with a predetermined operating speed.

FIG. 13 is a flowchart showing a main part of an example of the systemactivation process concerning the (2-2) serial system. FIG. 13 showsonly differences from the example of the process described concerningthe (1) analog system.

In step ST30, for example, the sensor detection value and the thresholdvalue are compared by the comparator 15. If the sensor detection valuesatisfies a condition defined by the threshold value, the processproceeds to step ST31. If not, the sensor detection value iscontinuously monitored.

In step ST31, the comparator 15 interrupts the arithmetic processingsection 17 through the serial communicator 21, and the sleep state iscanceled in the arithmetic processing section 17. This allows thearithmetic processing section 17 in step ST32 to be in a state capableof performing processing with a predetermined operating speed.

The subsequent processing is as described with reference to FIG. 9.After the CPU core or the like forming the arithmetic processing section17 is set to the sleep state in step ST7, the process returns to stepST30 in FIG. 13.

Since, in this system, serial data communication is used for informationtransfer between the detecting unit 13B and the second control unit 4 b,this system has advantages such as ability to transmit and receive amore amount of information compared with the (2-1) binarization system.Accordingly, also an arithmetic processing section using a CPU or thelike can re-compare data. Thus, flexible responses are possibleconcerning sensor recognition. In addition, an interruption is generatedsuch that the detection data from the detecting unit 13B is sent to thesecond control unit 4 b through serial communication. Thus, the secondcontrol unit 4 b can operate in a state (power saving mode) having lowpower consumption.

As described above, in the (1) analog system, in comparison between thedetecting unit and the second control unit 4 b, the configuration of thedetecting unit is simplified. In the (2) digital systems, theconfiguration of the second control unit 4 b is simplified.

Next, form (III), that is, the configuration for enhancing detectionaccuracy by combining detection of contact with the device and detectionof a change in attitude of the device, is described below.

For example, when an electrostatic sensor detects contact of fingerswith a camera body, and an angular velocity sensor detects, as a changein velocity, a change in attitude in holding the camera, it isdetermined that the image capturing mode is set, and the systemactivation process is performed.

FIG. 14 shows a setting method example concerning system activation.Examples of screens are shown in portions (A) to (H) of FIG. 14. In thissetting method example, as setting items concerning three types of mode,“INSTANT START,” “NORMAL,” “HIGH SPEED,” “MAXIMUM SPEED,” areselectable.

Portions (A) to (C) are similar to those in FIG. 5. In each of portions(C) and (D), for the item “INSTANT START,” a “NORMAL” mode is set.

The user performs a “right” directional operation in a state in whichthe cursor is positioned in the item “INSTANT START” as shown in portion(D) of FIG. 14, whereby, as shown in portion (E), for the “INSTANTSTART,” one of three modes becomes selectable.

Since, in this setting method example, the “NORMAL” mode has been set,by performing a “downward” directional operation with a cross key or thelike, as shown in portion (F) of FIG. 14, the user can position thecursor on a “HIGH SPEED” mode. By further performing the “downward”directional operation, as shown in portion (G) of FIG. 14, the user canposition the cursor on a “MAXIMUM SPEED” mode.

After that, by confirming the selected item, that is, pressing thecenter part (determination button) of the cross key or the like, thescreen is changed to the screen shown in portion (H) of FIG. 14 and thesetting operation finishes.

The above consecutive operations enable the “INSTANT START” to be set toa desired mode.

Next, an example configuration in which the (1) analog system and the(2) digital systems are applied to form (III) is described below.

At first, the configuration form of the form (I) is described below. InFIG. 7, for example, the detecting unit 13 includes an electrostaticsensor and an angular velocity sensor, or an acceleration sensor, and ananalog signal (indicated by the broken line arrow in FIG. 7) output byeach sensor is sent to the A/D converter 14. The data storage section 16stores, in units of sensors, threshold data that is written in shippingby using the data writing device 18. The threshold data of each sensoris read and sent to the comparator 15.

FIG. 15 is a flowchart showing a main part of the example of the systemactivation process in a case in which the above “HIGH SPEED” mode isset. FIG. 15 shows differences from the example of the process describedwith reference to FIG. 8.

After a detection signal of each sensor is sent to the second controlunit 4 b, in step ST40, detection data by the electrostatic sensor andthe threshold data from the data storage section 16 are sent andcompared with each other in the comparator 15. If the detection datasatisfies a condition defined by the threshold data, the processproceeds to step ST41. If not, the sensor detection value iscontinuously monitored.

In step ST41, detection data (data obtained by A/D conversion) by theangular velocity sensor (or acceleration sensor) and the threshold datafrom the data storage section 16 are sent and compared with each otherin the comparator 15. If the detection data satisfies a conditiondefined by the threshold data, the process proceeds to step ST42. Ifnot, the process returns to step ST40, and the sensor detection data iscontinuously monitored.

In step ST42, processing that is necessary for awaking the arithmeticprocessing section 17 from the sleep state is performed. In other words,the comparator 15 generates an interruption signal for the arithmeticprocessing section 17, whereby its sleep state is canceled. This allowsthe arithmetic processing section 17 in step ST43 to perform processingwith a predetermined operating speed. The process proceeds to step ST4shown in FIG. 9.

The subsequent processing is as described with reference to FIG. 9.After, in step ST7, the CPU core or the like forming the arithmeticprocessing section 17 is set to the sleep state, the process returns tostep ST40 shown in FIG. 15.

In this example, the detection with the electrostatic sensor, that is,contact detection, is initially performed. In addition to that, deviceattitude detection may initially be performed. For example, in stepST40, the detection data with the angular velocity sensor oracceleration sensor and the threshold data may be compared with eachother, and, in step ST41 the detection data with the electrostaticsensor and the threshold data may be compared with each other.

In any case, the contact detection and the attitude detection ensuredetermining that the image capturing mode is set, and the systemactivation is performed.

FIG. 16 is a flowchart showing a main part of an example of the systemactivation process in a case in which the above “MAXIMUM SPEED” mode isset. FIG. 16 shows differences from those in the example of the processdescribed with reference to FIG. 8.

After the detection signal of each sensor is sent to the second controlunit 4 b, in step ST50, the detection data (data obtained by A/Dconversion) with the electrostatic sensor and the threshold data fromthe data storage section 16 are sent and compared with each other in thecomparator 15. If the detection data satisfies a condition defined bythe threshold data, the process proceeds to step ST51. If not, theprocess proceeds to ST53.

In step ST51, processing that is necessary for awaking the arithmeticprocessing section 17 from the sleep state is performed. In other words,the comparator 15 generates an interruption signal for the arithmeticprocessing section 17, whereby its sleep state is canceled. This allowsthe arithmetic processing section 17 in step ST52 to perform processingwith a predetermined operating speed. The process proceeds to step ST4shown in FIG. 9.

In step ST53, the detection data (data obtained by A/D conversion) withthe angular velocity sensor or acceleration sensor and the thresholddata from the data storage section 16 are sent and compared with eachother in the comparator 15. If the detection data satisfies a conditiondefined by the threshold data, the process proceeds to step ST54. Ifnot, the process returns to step ST50, and the sensor detection value iscontinuously monitored.

In step ST54, processing that is necessary for awaking the arithmeticprocessing section 17 from the sleep state is performed. In other words,the comparator 15 generates an interruption signal for the arithmeticprocessing section 17, whereby its sleep state is canceled. This allowsthe arithmetic processing section 17 in step ST55 to perform processingwith a predetermined operating speed. The process proceeds to step ST4shown in FIG. 9.

Although the subsequent processing is as described with reference toFIG. 9, in step ST7, the CPU core or the like forming the arithmeticprocessing section 17 is set to the sleep state before the processreturns to step ST50 shown in FIG. 16.

In FIG. 16, for ease of understanding, the contact detection and theattitude detection are separately shown, but steps ST51 and ST54 aresubstantially identical in processing and steps ST52 and ST55 aresubstantially identical in processing. Thus, for example, if, in stepST50, the contact detection value satisfies a threshold condition, theprocess may proceed to step ST54 (steps ST51 and ST52 are not necessaryin this case).

Although, in this example, the detection with the electrostatic sensor,that is, the contact detection, is initially performed, this example isnot limited to this manner. The device attitude detection may initiallybe performed, that is, for example, in step ST50, the detection datawith the angular velocity sensor or acceleration sensor and thethreshold data may be compared with each other, and, in step ST53, thedetection data with the electrostatic sensor and the threshold data maybe compared with each other.

In any case, when the contact detection or the attitude detectionindicates that the image capturing mode is set, the system activationprocess is immediately performed.

Next, the (2-1) binarization system is described below.

In FIG. 10, for example, the detecting unit 13A includes anelectrostatic sensor or angular velocity sensor, or an accelerationsensor. An output signal from each sensor is sent to the comparator 15.The data storage section 16 stores, in units of sensors, threshold datathat is written in shipping by using the data writing device 18. Thethreshold data of each sensor is read and sent to the comparator 15.Alternatively, by using the external circuit 19 for the comparator 15 toadjust a constant value for each sensor in shipping, each thresholdvalue is set.

An output of the comparator 15, that is, a binary signal, is sent to theinterruption generating section 20, whereby the arithmetic processingsection 17 is interrupted.

A main part of an example of the system activation process in a case inwhich the “HIGH SPEED” mode is set is described below with reference toFIG. 15.

After the detection signal of each sensor is sent to the second controlunit 4 b, in step ST40, the detection signal with the electrostaticsensor and a signal representing a threshold value for the detectionsignal are compared with each other by the comparator 15. If the sensordetection signal satisfies a condition defined by the threshold value,the process proceeds to step ST41. If not, the sensor detection signalis continuously monitored.

In step ST41, the detection signal with the angular velocity sensor oracceleration sensor and the threshold value signal are sent and comparedwith each other in the comparator 15. If the sensor detection valuesatisfies the condition defined by the threshold value, the processproceeds to step ST42. If not, the process returns to step ST40, and thedetection value is continuously monitored.

In step ST42, after the binary signal is sent from the comparator 15 tothe interruption generating section 20, an interruption signal generatedby the interruption generating section 20 is sent to the arithmeticprocessing section 17, whereby its sleep state is canceled. This allowsthe arithmetic processing section 17 in step ST43 to perform processingwith a predetermined operating speed. The process proceeds to step ST4shown in FIG. 9.

Although the subsequent processing is as described with reference toFIG. 9, the CPU core or the like forming the arithmetic processingsection 17 is set to the sleep state before the process returns to stepST40 shown in FIG. 15.

In a form in which the device attitude detection is initially performed,for example, in step ST40, the detection value with the angular velocitysensor or acceleration sensor and the threshold value may be comparedwith each other, and, in step ST41, the detection value with theelectrostatic sensor and the threshold value may be compared with eachother.

In any case, on the basis of the binary signal, it is ensured that theimage capturing mode is set by the contact detection and the attitudedetection.

In the example of the system activation process in the case in which the“MAXIMUM SPEED” is set, in FIG. 16, at first, the detection signal ofeach sensor is sent to the second control unit 4 b.

In step ST50, the detection signal with the electrostatic sensor and asignal representing a threshold value of the detection signal arecompared with each other by the comparator 15. If the sensor detectionsignal satisfies a condition defined by the threshold value, the processproceeds to step ST51. If not, the process proceeds to step ST53.

In step ST51, the binary signal from the comparator is received by theinterruption generating section 20. This generates an interruptionsignal for the arithmetic processing section 17, whereby its sleep stateis canceled. In step ST52, the arithmetic processing section 17 enters astate capable of performing processing with a predetermined operatingspeed. The process proceeds to step ST4 shown in FIG. 9.

In step ST53, the detection signal with the electrostatic sensor oracceleration sensor and the threshold value signal from the data storagesection 16 are sent and compared with each other in the comparator 15.If the sensor detection value satisfies a condition defined by thethreshold value, the process proceeds to step ST74. If not, the processreturns to step ST50, and the sensor detection value is continuouslymonitored.

In step ST54, the binary signal is received from the comparator 15 bythe interruption generating section 20. This generates an interruptionsignal for the arithmetic processing section 17, whereby its sleep stateis canceled. In step ST55, the arithmetic processing section 17 enters astate capable of performing processing with a predetermined operatingspeed. The process proceeds to step ST4 shown in FIG. 9.

Although the subsequent processing is as described with reference toFIG. 9, in step ST7, the CPU core or the like forming the arithmeticprocessing section 17 is set to the sleep state before the processreturns to step ST50 shown in FIG. 16.

In the form in which the device attitude detection is initiallyperformed, for example, in step ST50, the detection value with theangular velocity sensor or acceleration sensor and the threshold valuemay be compared with each other, and, in step ST53, the detection valuewith the electrostatic sensor and the threshold value may be comparedwith each other.

In any case, when, on the basis of the binary signal, it is ensured thatthe image capturing mode is set by the contact detection or attitudedetection, the system activation process is immediately performed.

Next, the form of the (2-2) serial system is described below.

In FIG. 12, for example, the detecting unit 13B includes anelectrostatic sensor and angular velocity sensor, or an accelerationsensor. An output signal of each sensor is sent to the comparator 15, oris sent to the arithmetic processing section 17 through serialcommunication. The data storage section 16 stores, in units of sensors,threshold data that is written in shipping by using the data writingdevice 18. Threshold data of each sensor is read and sent to thearithmetic processing section 17. Alternatively, by using the externalcircuit 19 for the comparator 15 to adjust a constant value for eachsensor, each threshold value is set.

The output signal of the comparator 15 is sent to theserial-communication-and-interruption-generating section 22 included inthe second control unit 4 b through the serial communicator 21. Aninterruption signal generated by the serial communicator 21 is sent tothe arithmetic processing section 17. Alternatively, detection data fromthe detecting unit 13B is transmitted and compared with the thresholdvalue from the data storage section 16 in the arithmetic processingsection 17.

In the example of the system activation process in the case in which the“HIGH SPEED” mode is set, in FIG. 15, the detection signal of eachsensor is sent to the second control unit 4 b.

In step ST40, for example, the detection signal with the electrostaticsensor and a signal representing a threshold value of the detectionsignal are sent and compared with each other in the comparator 15. Ifthe sensor detection value satisfies a condition defined by thethreshold value, the process proceeds to step ST41. If not, the sensordetection value is continuously monitored.

In step ST41, the detection signal with the angular velocity sensor oracceleration sensor and the threshold value signal are compared by thecomparator 15. If the sensor detection value satisfies a conditiondefined by the threshold value, the process proceeds to step ST42. Ifnot, the process returns to step ST40, and the sensor detection value iscontinuously monitored.

In step ST42, the signal is sent from the comparator to theserial-communication-and-interruption-generating section 22 through theserial communicator 21, and an interruption signal generated by theserial-communication-and-interruption-generating section 22 is sent tothe arithmetic processing section 17, whereby its sleep state iscanceled. This allows the arithmetic processing section 17 in step ST43to perform processing with a predetermined operating speed. The processproceeds to step ST4 shown in FIG. 9.

Although the subsequent processing is as described with reference toFIG. 9, in step ST7, the CPU core or the like forming the arithmeticprocessing section 17 is set to the sleep state before the processreturns to step ST40 shown in FIG. 15.

Although, in this example, the detection with the electrostatic sensor,or the contact detection, is initially performed, a detection manner isnot limited to this example. By initially performing the device attitudedetection, for example, in step ST40, the detection value with theangular velocity sensor or acceleration sensor and the threshold valuemay be compared, and, in step ST41, the detection value with theelectrostatic sensor and the threshold value may be compared.

In any case, serial communication is used to ensure determining that theimage capturing mode is set by the contact detection and the attitudedetection, and the system activation process is performed.

In a form that does use the comparator 15 in the detecting unit 13B, insteps ST40 and ST41, the detection data of each sensor is sent to thearithmetic processing section 17 through serial communication, wherebythe arithmetic processing section 17 is interrupted. In the arithmeticprocessing section 17, each detection value is compared with thethreshold value from the data storage section 16. When the comparisonresult indicates the start of changing to the image capturing mode, theprocess directly proceeds from step ST41 to step ST43, and the CPU coreor the like enters a state capable of performing processing with apredetermined operating speed.

In the example of the system activation process in the case in which the“MAXIMUM SPEED” mode is set, in FIG. 16, at first, the detection signalof each sensor is sent to the second control unit 4 b.

In step ST50, for example, the detection signal with the electrostaticsensor and the threshold value signal are compared by the comparator 15.If the sensor detection value satisfies a condition defined by thethreshold value, the process proceeds to step ST51. If not, the processproceeds to step ST53.

In step ST51, the signal is sent from the comparator to theserial-communication-and-interruption-generating section 22 through theserial communicator 21, whereby an interruption signal is generated forthe arithmetic processing section 17, and its sleep state is canceled.In step ST53, the arithmetic processing section 17 enters a statecapable of performing processing with a predetermined operating speed.The process proceeds to step ST4 shown in FIG. 9.

In step ST53, the detection signal with the angular velocity sensor oracceleration signal and the threshold value signal from the data storagesection 16 are sent and compared with each other in the comparator 15.If the sensor detection value satisfies a condition defined by thethreshold value, the process proceeds to step ST54. If not, the processreturns to step ST50, and the sensor detection value is continuouslymonitored.

In step ST54, the signal is sent from the comparator to theserial-communication-and-interruption-generating section 22 through theserial communicator 21. This generates an interruption signal for thearithmetic processing section 17, and its sleep state is canceled. Instep ST55, the arithmetic processing section 17 enters a state capableof performing processing with a predetermined operating speed. Theprocess proceeds to step ST4 shown in FIG. 9.

Although the subsequent processing is as described with reference toFIG. 9, in step ST7, the CPU core or the like forming the arithmeticprocessing section 17 is set to the sleep state before the processreturns to step ST50 shown in FIG. 16.

In a form in which the device attitude detection is initially performed,for example, in step ST50, the detection value with the angular velocitysensor or acceleration sensor and the threshold value may be comparedwith each other, and, in step ST53, the detection value with theelectrostatic sensor and the threshold value may be compared with eachother.

In any case, when serial communication is used to find that the imagecapturing mode is set by the contact detection or the attitudedetection, the system activation process is immediately performed.

In the form that does use the comparator 15 in the detecting unit 13B,in steps ST50 and ST53, the detection data of each sensor is sent to thearithmetic processing section 17 through serial communication, and eachdetection value is compared with the threshold value from the datastorage section 16 by the arithmetic processing section 17. When thecomparison result indicates the start of changing to the image capturingmode, the process proceeds to step ST52 or ST55, and the CPU core of thelike enters a state capable of performing processing with apredetermined operating speed.

According to the above-described configurations, for example, thefollowing advantages are obtained.

Regarding Activating Functionality of System

In an image capturing device of the related art, it takes a time ofapproximately one second after pressing a power supply switch tocompletion of activation, even if the image capturing device has fastactivating functionality. Accordingly, if a user of the device has amoment for capturing an image of a subject that passes instantly, asituation in which the user fails to perform image capturing occurs.Unlike that, as described above, by using a sensor, such as anelectrostatic sensor or angular velocity sensor, to detect changing toan image capturing mode and a preparatory operation, and activating thesystem of the device in background without informing the user, a statein which image capturing can be immediately initiated can be guaranteed.As a result, a possibility of missing a shutter release opportunity isdecreased.

Regarding Power Consumption of System

It is difficult to reduce a system activation time to zero. Thus, forexample, in a method for ensuring a state capable of image capturing bycontinuously supplying power to the system, in compensation therefor, anincrease in power consumption inevitably shortens a time of drivingusing a battery. This causes a problem in convenience. Specifically, itis necessary to carry a charged battery or the like on hand. Unlikethat, as described above, in order to monitor detection of contact withthe device, detection of a device attitude, a switch operation, etc.,the device is set to a standby state with minimum necessary powerconsumption, and, when it is found that an image capturing mode is setin the device, supplying of power to the system is fully initiated tochange the device state to a state capable of image capturing. In otherwords, the system power is not continuously on, so that unnecessarypower is prevented from being consumed in a waiting state in which theuser does not intend to perform image capturing. Thus, a power savingeffect is sufficiently obtained, and, in application of an embodiment ofthe present invention to portable devices, a battery life can beextended.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. An activation method for an image capturing device having a functionof controlling power supplying operation, the image capturing devicehaving a plurality of operational states including a first operationalstate capable of image capturing operation and a second operationalstate, wherein power consumption of an unit of the image capturingdevice in the second operational state is less than power consumption ofthe unit in the first operational state, the activation methodcomprising: in the second operational state, monitoring a user's touchoperation to a touch sensor of the image capturing device; and when auser's touch operation instructing a change to the image capturingoperation is detected in the second operational state, changing thesecond operational state to the first operational state and supplyingpower to the unit so that the unit becomes capable of working in theimage capturing operation.